TIP OF THE WEEK

4) answer: dWhile many experts recommend taking 400 micrograms of folic acid daily, the researcher who demonstrated this B vitamin’s role in preventing neural-tube defects says the dosage should be increased about tenfold. Nicholas Wald, F.R.C.P., F.R.S., director of the Wolfson Institute of Preventive Medicine and professor of environmental and preventive medicine at Barts and The London School of Medicine and Dentistry, recommends that all women start taking 5 milligrams of folic acid daily two weeks before trying to conceive and continuing that dosage for at least the first 12 weeks of pregnancy.

“Taking .4 milligrams [400 micrograms] of folic acid will prevent about 40 to 50 percent of neural-tube defects,” Wald says. “Taking 5 milligrams will prevent about 80 percent.” While the American College of Obstetricians and Gynecologists (ACOG) recommends that women who have had a child with a neural-tube defect take 4 milligrams of folic acid daily and that others take 400 micrograms, Wald points out that there are no risks associated with the higher dosage.

Folic acid is available either by prescription or over the counter. If you don’t have a prescription, find a supplement that contains only folic acid; taking higher doses of a multivitamin could lead to toxic levels of other nutrients, such as vitamin A.

5) answer: aProducts such as hair dyes, perms and straighteners have not been shown to pose a risk to the average pregnant woman, Filkins says. (Women who work in the beauty industry and are therefore exposed contin-uously, and in larger amounts, to the chemi-cals in these products may have a higher risk of miscarriage.) To be on the safe side, wait until after the first trimester to have any of these treatments done. In addition, limit hair coloring to once every eight weeks. Switch from permanent color, which sits on your scalp, to highlights, as dye may be absorbed into the bloodstream through the scalp.

Nail polish and self-tanners also have not been proven unsafe, but limit unnecessary exposure. Some nail polish brands now offer formulas free of a suspect chemical, dibutyl phthalate (DBP), but not all list their ingredients. And choose a nail salon with good ventilation. “The less ventilation, the bigger the exposure,” Filkins says. Self-tanners do not seep into the skin; still, it’s prudent to avoid applying these products to your belly while pregnant and to your breasts if you are nursing.